“Cogito cogito ergo cogito sum -- "I think that I think, therefore I think that I am;" as close an approach to certainty as any philosopher has yet made.”
“Cogito ergo sum. (I think, therefore I am.)”
“Dubito, ergo cogito, ergo sum.(English: "I doubt, therefore I think, therefore I am")”
“I am not much for philosophy, but that old Descartes, he got me thinking. And therefore being. Anyone? Anyone? Cogito ergo sum jokes? No? Okay.”
“Cogito ergo sum, certamen ergo sum.”
“One can ask why the I has to appear in the cogito {Descartes’ argument “I think therefore I am.}, since the cogito, if used rightly, is the awareness of pure consciousness, not directed at any fact or action. In fact the I is not necessary here, since it is never united directly to consciousness. One can even imagine a pure and self-aware consciousness which thinks of itself as impersonal spontaneity.”